1. Field of the Invention
The present invention relates to a sidelight-type spread illuminating apparatus including a light guide plate that has a light source disposed at a light incident end surface thereof and emits illumination light in a spread pattern from an emitting part.
2. Description of the Related Art
As an illumination unit for a liquid crystal display panel, a sidelight-type spread illuminating apparatus (backlight) in which a light source that emits white light is disposed along a side end surface of a light guide plate is widely utilized. There have been efforts in the past to make such spread illuminating apparatuses thinner and brighter and improve their brightness uniformity and the like. However, recently there has been increased demand for further enhancements to the color tone uniformity of emitted light in accordance with advancements in high definition of liquid crystal display panels. Conventionally, with regard to color tone uniformity, most development has been exclusively geared towards measures for eliminating color unevenness that occurs across the entire emitting surface of the light guide plate (for example, refer to Japanese Patent Application Laid-Open (JP-A) No. 2005-347010 and Japanese Patent Application Laid-Open (JP-A) No. 2012-94283).